No vice president has ever done so much so quickly -- or made such a difference.

In foreign affairs, Joe Biden has taken more trips abroad than any vice president this early in a term, and none of them have been fluff. In Munich, he delivered the administration's first major foreign policy address. In Latin America, he set the stage for President Obama's trip to the Summit of the Americas. In the Balkans, Biden got the peace process back on track. And his visit to Beirut was key to helping the pro-Western government there win its election last weekend.

Domestically, President Obama credits his vice president with winning the votes needed to pass the American Recovery and Reinvestment Act -- and then Biden took on the thankless task of implementing it. He's gotten $150 billion out the door quickly and without waste, and Cabinet members tell me that Biden's leadership is making this massive program work. His Task Force on Middle Class Working Families is making sure that average families aren't forgotten when policy is made.

Maybe Joe Biden sometimes says too much, too honestly. But after eight years of secrecy under Dick Cheney, Biden's "tell it like it is" style is a change I can believe in.

MARY MATALIN

Assistant to President George W. Bush; adviser to Vice President Dick Cheney; author

Historically, the office of the vice president has been characterized as "not worth a bucket of warm spit"; its function described as "they die, he flies"; its holders maligned, ignored and/or unceremoniously removed. At best, it has served as political purgatory for presidential aspirants. George W. Bush's selection of Dick Cheney radically upgraded the vice presidency to prime political real estate. Joe Biden's tenure will be evaluated by this standard.

Biden measures up well on three key political elements: (1) He has no personal political ambitions to dilute his loyalty to President Obama's agenda; (2) he attracted a first-rate staff with deep and wide policymaking experience, as well as important political relationships; (3) he has his own foxhole-buddy history in the Senate, a critical validating clearinghouse for Obama's less valid policy prescriptions.

On singular vice presidential policy tasks, Biden's performance can only be graded "jury's still out." In a comparable period, in addition to his integral work on new economic policies, Cheney had already completed a comprehensive energy plan and was deep into modernizing what was then called Homeland Defense. Biden's signature assignment is the efficient and effective distribution of stimulus funds, the successful execution thereof defined by the president as "targeted, timely, temporary" and job-producing. By any measure, none of the president's objectives have yet been met, and support for the program dwindles daily.

As for the powerful, and essential, function of message magnifier, Biden is often more helpful to the president's opponents than to the president. Cheney was the go-to message magnifier for all big subjects. We deemed him the E.F. Hutton of message deliverers: When he talked, they listened. Unfortunately, too often for Biden, when he talks, they giggle. A veep's greatest function is the least detectable. The best of the Bush model was the private give and take between the president and vice president. Only Barack Obama can evaluate Biden in that respect.

STEPHEN HESS

Senior fellow emeritus at the Brookings Institution; author, most recently, of "What Do We Do Now? A Workbook for the President-Elect."

An outstanding senator was elected vice president; six months later he's the butt of late-night comics' jokes. Craig Ferguson says, "Biden speaks the language of crazy"; Jimmy Fallon calls him "Chewbacca with fur plugs."

We learned during the campaign what Obama had in mind for Biden. During the veep debate, after Sarah Palin claimed she would lead on "energy independence . . . reform of government . . . families of children with special needs," Biden replied that "when [Obama] asked if I wanted a portfolio, my response was no. . . . He's president, not me, I'll give my best advice."

An appropriate answer. I remember, when helping Richard Nixon write an essay on the vice presidency in 1962, his feeling that presidents should stop loading their vice presidents with odd jobs, creating, as he put it, a sort of Cabinet Secretary for Catch-All Affairs.

But within days of their inauguration, Obama began filling Biden's dance card, including with a Task Force on Middle Class Working Families to "conduct outreach sessions with representatives of labor, business, and the advocacy communities" (apparently the president would otherwise not know what's on their minds). And so the vice president circles the country and the world, doing things and occasionally saying things that amuse the comics more than the president.

What should Biden be doing? No one in Obama's circle knows the Senate better or is more respected on Capitol Hill. As the legislative process moves into heavy lifting, Biden's place is at the president's ear. Joe: Stay home, shut up, advise.

ROBERT DALLEK

Historian and author

A hundred years ago the vice presidency was seen, in Theodore Roosevelt's words, as "not a stepping stone to anything except oblivion." All this changed in the 20th century, when seven U.S. vice presidents also served as president and most holding the job, especially after 1952, saw it as a launching pad for a presidential bid.

At the age of 66, with a history of health problems and with no prospect of running for the presidency until 2012, Joe Biden seems unlikely to even reach for the Oval Office. Instead, he and President Obama have mapped out a strategy that takes advantage of Biden's 36-year Senate career.

Despite his reputation for verbosity and occasional gaffes, which he has lived up to as vice president, Biden has been an effective point man on Obama's Iraq, Afghanistan and Pakistan policies; the economic recovery plan, including chairing the White House Task Force on Middle Class Working Families; and the selection of Sonia Sotomayor as the administration's first Supreme Court nominee.

Comparing the vice president to the basketball player "who does a bunch of things that don't show up on the stat sheet," Obama has chosen someone who suits the current mold of an activist vice president more attentive to the administration's needs than to personal plans for future campaigns.

MICHAEL S. BERMAN

Counsel and deputy chief of staff to Vice President Walter Mondale; president of the Duberstein Group

A vice president has only one constituent who matters, only one person to whom he is really accountable: the president. And all signs are that Barack Obama likes the job Joe Biden is doing.

Biden has hit the ground running and is making a significant contribution to the administration. He is following the model of the modern vice presidency established by Walter Mondale -- serving as an across-the-board counselor to the president, bringing his experience and wisdom to White House decision-making. But he has also added dimensions of Al Gore's approach, taking on a limited number of major projects that are critical parts of the president's agenda. He has, for example, a key role in implementation of the American Recovery and Reinvestment Act and substantial involvement in the confirmation of the president's first Supreme Court nominee.

Biden brings to his various roles his understanding of Congress and the government and a connection to significant constituencies in the Democratic Party. While he has a public image as someone who sometimes talks more than he should, the word from within the White House is that he is disciplined, forceful and insightful.

ED ROGERS

White House staffer to Ronald Reagan and George H.W. Bush; chairman of BGR Group

Joe Biden is doing downright just fine. Is just fine good enough?

Maybe he isn't deputy president but is, in fact, the president in waiting. Biden is busying himself with worthwhile initiatives, he is not a part of any Obama administration infighting, everybody takes him seriously, and he has a solid staff.

It has become expected to label each new vice president as the most powerful so far. Maybe that hit a crescendo with Dick Cheney, and perhaps it is good that we have a more traditional V.P. Is Biden, of all people, destined to be the quiet vice president?

Maybe he is learning new tricks. The Senate is full of mindless talking, and when he was there he fit right in. Downshifting his daily word count has been an adjustment but no harm done, and the media mostly has his back.

So far, so good. He is a net plus.

MICHAEL FELDMAN

Former senior adviser to Vice President Al Gore; founding member of the Glover Park Group

Thirty-six years in the Senate interacting with seven presidents clearly taught Joe Biden a few things about how White Houses work. He knew when he joined the ticket that a vice president's influence depends, more than anything else, on his relationship with the president. If you don't get that part right, your chances of success are low.

Biden has made himself valuable to President Obama in two key ways. First, rather than work on a portfolio of discrete issues, he serves as the president's all-purpose adviser and surrogate on everything from major domestic policies (implementing the stimulus) and difficult national security decisions (the troop increase in Afghanistan) to Supreme Court nominations (he interviewed all the finalists) and sensitive foreign travel (he visited Lebanon right before last weekend's elections). Second, Biden acts as the president's back-channel liaison to his former colleagues in the Senate, where he has close personal relationships with both Democrats and Republicans. Biden helped deliver vital Republican votes for the stimulus bill and played a key role in persuading his old friend Arlen Specter to switch parties.

At 66, Biden isn't going to change. He is famously candid, sometimes to his detriment. But candor is something a president desperately needs when he's seeking advice from his inner circle.

MARY BETH CAHILL

Manager of Sen. John Kerry's presidential campaign; former chief of staff to Sen. Edward M. Kennedy

Vice President Biden is establishing himself as a major asset to the Obama administration. He is doing exactly what the president tapped him for, working his long relationships on the Hill and in the press to further the goals of the White House. Whether it is working out in the Senate gym so that he can take private soundings from former colleagues or traveling the country in support of the stimulus package, Biden has thrown himself into his new assignment with gusto. He is enjoying the job, and it shows, making governing in these terrible times look like a challenge to be savored. He also makes clear the primacy of President Obama in every situation, and his straightforward reports of Secretary of State Hillary Clinton having the final word on international matters signals that the "team of rivals" approach is working. He gives advice privately to the president at their weekly lunch, and it remains private, a benefit to both as they further a trusting relationship.

That said, Obama knew this running mate would come with an occasional gaffe, a career-long reality for Biden. That has continued to be the case, though nothing has been detrimental to Biden or the administration.